MOTM

I've been hearing a lot of talk about people wanting modular DX-7 clones.

This doesn't seem to make a whole lot of sense to me.  When you're in 
the analog world, you can patch together a fairly complex FM patch using 
analog oscillators, but anything past a few 'operators' worth of 
emulating a digital FM synth will result in a lot of mush. VCOs just 
seem to act flaky when you push them like this.  Maybe this isn't the 
case with beasts like the MOTM-300, but as far as I know, trying to do 
analog FM past the level of complexity you get with maybe 3 chained VCOs 
doesn't work predictably like digital FM does.  So, if my understanding 
of the limits of using analog data to accomplish FM is correct, you'd 
need to be sending *digital* data from operator module to operator 
module.  Sure, you could send digital data out over the same patch cords 
you use, the cables don't care if they're  carrying S/PDIF or +-5 Volts 
analog audio.  But this means you can't patch through your other analog 
modules.

Perhaps this would work using digital oscillators sending out and taking 
in analog signal, but this means that each module is going to need a set 
of DACs and ADCs, and it's going to need to figure out exactly what the 
signal coming in is, for example convert the audio-version of the sine 
wave it 'hears' to a mathematically perfect sine wave?  Maybe this 
wouldn't be neccesary, but it does seem that it would be to me.

As far as I can tell, getting 'real' DX-7 emulation via modules would 
require digital modules with digital inputs and outputs, which would 
preclude any passing of operators through things like the wavewarper.

-Geoff

Jeff Laity wrote:

> What sounds interesting to me is modular FM. The DX-7 algorithm could 
> be replaced by a patchbay of jacks. This way, operator 4 could be 
> processed through a Wavewarper before modulating operator 1. Each 
> input would have its own pitch control and CV (with LED frequency 
> display), as well as level CV.
>
> Hey, I just designed a $600 module. Perhaps I should back off a bit. I 
> actually like the Additive module idea better, since much of this FM 
> and AM can already be done on MOTM with 300s and Wavewarpers.
>
> On Feb 11, 2005, at 8:10 AM, Eric Frampton wrote:
>
>     Ivan Wrote:
>
>     > I would think that future digital MOTM products should be unique;
>     > there are already DX-7's in a box, for example (I've got a a
>     couple of
>     > them inside my Kenton PlugStation).
>     >
>     > Personally I'm still looking forward to the MOTM Bi-Phase.  There
>     > isn't anything quite like that currently on the market.
>
>     I agree with both of these things, though if I know Paul S's like I
>     think I do, his "DX-7 on a chip" reference probably was meant more as
>     an "imagine what we can do" than "I'd actually like to put a DX7 on a
>     chip".
>
>     I've got an 816 rack and a line on 2 more if anybody wants 'em. We
>     don't need to re-invent -that- wheel.
>
>     And I too am looking forward to a VC Bi-Phase!
>
>     e
>
>
>